Micrometer



Ap 1949- R. H. SACHTLEBER 2,467,499

MICROMETER Filed March 6, 1946 7 z 2e 33 24 21 9 3+ 3| 0 36 Fig 9 F 8INVENTOB ATTORNEY Patented Apr. 19, 1949 UNI ED STATES PATENT OFFICE 3Claims.

This: invention relates to micrometer gauges andia'naobject of thepresent invention is to pro vide a=microimeter which is easier tomanufacture than standard micrometers of approved type, and onerwhichwill have long life without impairment of its accuracy in that itsmovable work engaging parts will be subject to less wear than is hadinmicrometers of present day approved construction.

Another object: of the invention'is to provide amicrometer which is easyto read, one in which the:spindle.may be quickly moved to the Worktovbemeasured, and-one in which the worle engaging spindle does. notturn during the final settingthereby reducing'wear on the spindle andproviding more accurate measurements.

With-these and other objects in view, as may appear f-rom'theaccompanying specification, the invention consists of variousfea'tures'of construction'and combination of parts, which willbefirstdescribed" in connection with the accompanying drawings, showinga micrometer of a preferred form embodying the invention;and'the'features forming-the invention will be specifically pointed outin the claims.

In the drawings- Figure l-is'a top plan of the improved micrometer.

Figure-'2. is a side elevation of the micrometer. Figure=.-3.-is an endview of. the micrometer.

Figures-4 is a longitudinal section through themicrometer'taken on theline 4-dof Figure'l.

Figured is a cross-section taken on the line 5-5 of Figure 4.

Figure 6 is. a fragmentary vertical section through the micrometer takensubstantially on the line 6-4 of Figure 1.

Eigureflisa section takenon the line 7-'l'of Figure 6.

Figure 8 is a plan View of a friction member employed ina micrometerstructure;

Figure"9 is a section on the line 99 of Fig ure18.

Referring more particularly to the drawings the improved. micrometerincludesa body I having 2. depending accurate saddle or anvil carryingmember 2 formed thereon to which the micrometer anvi1i3 is attached inany. suitable manner. Afispindle 4 isadjustably'carried by the body 5and its Work engaging surface 5 co-operates with the work engagingsurface of the anvil 3 to measure work.

The spindle 4 has a portion of its outer surface externally screwthreaded as shown at 5 with the indicia carried portion 1 and theoperating portion 8 formed at the outer ends. The threaded portion 5- ofthe spindle 4 is threadably engaged: inthe internal screw threads ofthesleeve 9 and a knurled head. It) iscarried by the operating-l end 8of thespindle i for rotating the spindleto cause movement thereoflongitudinally of the sleeve 9; The sleeve 9 has external threads H onits outer. surface which co-operate with. the. internal threads l2 in asleeve l3. The sleeve.|3-- is carriedby the body l and is adjustablyconenected thereto by means of a threaded 00131166? tion Manda lock-nutstructure l5. This'adjuste able connection betweenthe body l and thesleeve ld will permit adjustment of the-spindle 4with: respect totherelativeportions of the sleeve 13;. sleeve 9 and-anvil il to compensatefor wear.

The threadson the outside of the sleeve 9:a-re'- larger and less in.number per inch, than-are: the internal threads-or the threads on theinside of the sleeve 9. relationof twenty (20) threads per inch-on'thef;outside of the sleeve 9 and twenty-five- (25): threads per inch on theinside of the sleever9; or in' any other. suitable relation" toeachother to provide the desired differences in speed; oft longitudinalmovement of the spindle by its'rota-e tion or: by the rotation of thethimble [6.

The sleeve 9 is connected to the thimble: 16: by a setscrew. l1 and thethimble lli'which: is in the-formofa sleeve-likeshell has graduationsaE8 on its tapered inner-end I9 which co-operatg:

with longitudinally extending graduations 20: formed on the outersurface of the body l. sleeve 9 which is the internal and externalthreaded'sleeve is connected to a rotating sleeve 2! by a'set-screw ordog-point screw Hand this:

rotatingrsleeveZ-l, bymeans of whichthersleeve; 9- is rotated isconnect'ed to'the thimble lfiaby" a friction clutch-structuregenerically indicated:

at 23', in-Eigure 4= of'the'drawings. The friction:

clutch structure-23- comprises a friction disc or ring -24-which engagesthe outer end of the thimbler lt and'has a spring ring 25 cOnnectedtheret'or by rivets. 26. has'pins 2T carried thereby which pins'enga'gein-openings'28 in thei'internal flange 29 formed: The" friction clutchstructure These threads may'be in*the"- The springring 25' is bowed and?30. The locking plunger or key 30 is spring pressed by means of a spring31 and it is carried by the anvil carrying saddle or member 2 as clearlyshown in Figures 6 and '7 of the drawings. A locking pin 32 is providedfor locking the plunger 30 in inoperative position out of the key- Way28. The locking pin 32 is slidably carried by the saddle 2 and movesinto and out of a groove 33 formed in the plunger 30. The movement ofthe locking pin 32 is limited by means of the pin 34 which rides in theslot 35 formed in the locking pin. The locking pin 32 may have anoperating head or lip 36 formed on its outer end.

In operation, when any piece of work is to be measured the work engagingend of the spindle 4 is moved inwardly away from the anvil 3 so that thepiece of work to be measured may be positioned between the spindle 4 andthe anvil 3. During this time the locking plunger 30 is held out of thekey-way 28 by the locking pin 32. The spindle is then moved forward byits rotation until it touches the work to be measured at which time thelocking pin 32 is moved out of locked position relative to the plunger30 and the plunger 30 then moves into the key-way by action of thespring 31. In the event that the plunger 30 and key-way are not inproper position for interengagement, the spindle is turned in reverse orleft hand direction for a part of a turn or until the key or lockingplunger 30 passes into the key-way 28. The spindle is thus lockedagainst rotary movement but is free to move longitudinally through thebody I, thus the spindle is moved against the work in close relationthereto for measuring the work. The accurate measurement of the work inthousandths of an inch is provided by the movement of the spindlefinally against the work through the rotation of the thimble l6 by meansof the sleeve 2! which gives the final accurate movement of the spindle.The friction clutch structure 23 is tensioned so as to prevent too tighta pressure between the spindle and the work. The thickness or diameterof the work being measured is then read on the scale 1 plus the scalesl8 and 20 which will give the accurate reading of the thickness ordiameter of the work in thousandths of an inch.

It will be understood that the invention is not to be limited tospecific construction or arrangement of parts shown, but that they maybe widely modified within the invention defined by the claims.

What is claimed is:

1. In a micrometer, a body having a stationary work engaging anvilthereon, a spindle extending through said body, and havin one endthereof co-operating with said anvil for measuring work, threads on saidspindle for a portion of its length, a sleeve provided with internalthreads and external threads, said external threads being larger andless in number to the inch than said internal threads, the threads onsaid spindle engaging said internal threads, a thimble rotatableindependently of said spindle and co-acting with said external threads,means connecting said thimble to said sleeve for rotating the sleeveupon rotation of the thimble, a second internally threaded sleeveco-operating with said external 4 thread for moving the thimble and saidfirst named sleeve longitudinally upon rotation of the thimble, andmeans adjustable on said second sleeve for adjusting the position ofsaid spindle to compensate for wear on the anvil.

2. In a micrometer, a body having a stationary work engaging anvilthereon, a spindle extending through said body and having one endthereof co-operating with said anvil for measuring work, threads on saidspindle for a portion of its length, a sleeve provided with internalthreads and external threads, said external threads being larger andless in number to the inch than said internal threads, the threads onsaid spindle engaging said internal threads, a thimble rotatableindependently of said spindle and co-acting with said ex ternal threads,means connecting said thimble to said sleeve for rotating the sleeveupon rotation of the thimble, a second internally threaded sleeveco-operating with said external thread for moving the thimble and saidfirst named sleeve longitudinally upon rotation of the thimble, meansadjustable on said second sleeve for adjusting the position of saidspindle to compensate for wear on the anvil, and locking means forlocking said spindle against rotation at predetermined times wherebysaid spindle will move longitudinally but not rotate upon combinedrotary and longitudinal movement of said thimble.

3. In a micrometer, a body having a stationary work engaging anvilthereon, a spindle extend ing through said body and having one endthereof co-operating with said anvil for measuring work, threads on saidspindle for a portion of its length,

a sleeve provided with internal threads and external threads, saidexternal threads being larger and less in number to the inch than saidinternal threads on said spindle engaging said internal threads, athimble rotatable independently of said spindle and co-acting with saidexternal threads,

means connecting said thimble to said sleeve for rotating the sleeveupon rotation of the thimble, a second internally threaded sleeveco-operating with said external thread for moving the thimble and saidfirst named sleeve longitudinally upon rotation of the thimble, meansadjustable on said second sleeve for adjusting the position of saidspindle to compensate for wear on the anvil, said spindle provided witha longitudinally extending key-way, a spring pressed locking key carriedby said body for engagement with said spindle to hold the spindleagainst rotation, and a locking plunger for holding said key out ofengagement 1 with said spindle.

RUDOLPH H. SACHTLEBER.

REFERENCES CITED The following references are of record in the file ofthis patent:

